“Jax is very excited but also a bit confused with the happy news he will have a little sister this fall. #grateful,” Arnold, 56, captioned a seriously cute snap of their little boy holding an ultrasound photo.

The couple are especially grateful to be expecting again after Arnold revealed on The Wendy Williams Showin January 2013 he went through 21 rounds of vitro fertilization throughout his past relationships because of his “low sperm count."

“I didn’t think it was in the cards for me, to be honest, and so I was completely shocked,” the funnyman later said after announcing Groussman’s first pregnancy on The View. “We’re really happy…it’s a miracle.”